Rotor for high-frequency alternating-current machines.



A. E. GUY. ROTOR FOR HIGH FREQUENCY ALTEENATING CURRENT MACHINES APPLICATION FILED APR. 10, 1909.

Patented Oct. 18, 1910.

Inventor: W 6- A ttys srArns earns-r ALBERT n. GUY, or rnnnron, NEW JERSEY, ASSIGNOR E0 on LAVAL STEAM TURBINE COMPANY, OF NEW YORK, N. Y., A CORPORATION OF NEW JERSEY.

ROTOR FOR HIGH-FREQUENCY ALTERNATING-CURRENT MACHINES.

Specification of Letters Patent.

Patented Oct. 18, 1910.

Application filed April 10, 1909. Serial No. 489,188.

T 0 all whom it may concern:

Be it known that I, ALBERT E. GUY, a citizen of the United States of America, and a resident of Trenton, county of Mercer, and State of New Jersey, have invented a cer tain new and useful Rotor for High-Frequency Alternating-Current Machines, of which the following is a specification.

My invention relates to improvements in rotors for alternating machines, the rotor herein described being adapted for use in machines of the inductor type, and being particularly intended for alternating current dynamos intended to generate currents of extremely high frequency. The rotary inductor or rotor is of the toothed type, being intended to rotate between the poles of suitable magnets.

In order to produce currents of the desired high frequency, the rotor is constructed to rotate with very high velocity, and is provided with a large number of teeth. It has been found essential, in such rotors, to provide filling of non-magnetic material bet-ween the teeth, as otherwise a very large proportion of the power required to revolve the rotor is expended in useless creation of air currents, the rotor acting as a centrifugal air fan. Also, owing to the air resistance, to the pull of the magnet poles, and to the severe centrifugal stresses, to which the teeth are subjected, it is neces sary to provide special means for securing extreme rigidity of the teeth and to prevent the teeth from flying out.

In the construction herein described, alternate teeth of the rotor are formed integrally therewith, the intermediate teeth being inserted from the side of the rotor and being held in place by means of suitable enlarged bases formed on the inserted teeth. For convenience in manufacture, it would be desirable to insert all of the teeth, instead of forming some integrally with the rotor; but where a very large number of teeth must be provided, I have found that it is impracticable, in a disk of reasonable diameter, to insert all of the teeth, as to do so would involve cutting away too great a proportion of the metal of the rim of the rotor. There fore, alternate teeth are formed integrally with the rotor, the intermediate teeth being inserted. To stiffen the teeth these inserted teeth are provided with circumferentiallyextending lugs which are substantially in contact with the integrally formed teeth; and to fill the spaces between the teeth, so as to reduce fan-action to a minimum, suitable filling pieces are provided, these filling pieces being preferably of a relatively soft and light metal, such as aluminum, and being held in place by the said projecting lugs of the inserted teeth. Also these filling pieces are preferably turned or upset into the spaces which they occupy, so that they fill such spaces very completely.

My invention consists therefore, in a toothed rotor comprising filling pieces between the teeth, whereby fan-action is reduced to a minimum; in a rotor, alternate teeth of which are formed integrally with a rotor disk and the intermediate teeth of which are inserted; in the novel means provided for bracing the teeth and for holding the filling pieces in place; and in other features hereinafter described and particularly pointed out in the claims.

The objects of my invention are to improve the construction of toothed rotors of alternating current machines, to reduce fan action to a minimum. to provide a very large number of teeth within a given peripheral space, to make the structure rigid and strong, to avoid possible flying out of the teeth or filling pieces, and to adapt the rotor for extremely high peripheral velocity.

I will now proceed to describe my invention with reference to the accompanying drawings.

In said drawings: Figure 1 shows aside elevation of the completed rotor. Fig. 2 shows an axial section of such rotor. Fig. 3 shows a fragmentary side elevation and partial section of the peripheral portion of the rotor, the section being taken on a plane parallel to the axis of rotation. Fig. 4 shows a perspective elevation of one of the inserted teeth and of two filling pieces arranged in proximity thereto. Fig. 5 shows an enlarged fragmentary section of the peripheral portion of the rotor, the section being taken on a plane passing through the axis of rotation.

In the drawings, 1 designates the rotor disk, such disk comprising preferably a single piece of metal of form adapting it for extremely high peripheral velocity and an extremely high rate of rotation, and being provided with a central aperture 2 for the reception of the driving shaft (not shown).

3, 3 designate integrally formed teeth proj ecting radially from the rim of the disk 1; l

and a, t designate inserted teeth alternated with the integrally formed teeth 3. These inserted teeth 4 are provided with somewhat enlarged bases 5 at the bottoms of which are bulbous enlargements 6; and in the rim of the disk 1 there are correspondingly-shaped sockets into which these pieces are received; the teeth being inserted from the side of the disk. These inserted teeth 4 are provided with circumferentially extending peripheral lugs 7 which abut against the adjacent integral teeth 3, so stiffening the toothed structure as a whole. These lugs 7 are somewhat narrower, transversely of the wheel, than are the teeth themselves.

8, 8 designate filling pieces adapted to be inserted between the teeth, such filling pieces being of non-magnetic material (the teeth themselves being of highly magnetic material-such for example as soft steel); the filling pieces being usually, in practice, of aluminum or a suitable aluminum alloy, though the use of other extremely light and non-magnetic metals, such for example, as magnesium and magnesium alloys, or other metals or alloys of the light-metal group, is not precluded but is regarded as within the scope of this invention. These filling pieces 8 are provided near their upper ends with notches 9 to receive the lugs 7 of the inserted teeth.

In assembling the inserted teeth and the filling pieces 8 on the rotor, two filling pieces are placed in their proper position with respect to one of the teeth a to be inserted, and these three parts are inserted to gether into the rotor, from one side of the rotor, the tooth 4 being driven into its socket 111 said rotor. lVhen all of the teeth and filling pieces have been assembled in this manner, the filling pieces 8 are tamped or hammered so as to upset them and cause them to fill completely the spaces between the teeth; and then the sides and peripheral surface of the rotor rim are finished so as to make such surfaces as smooth as possible, any projecting portions of the filling pieces being removed. The resulting structure is very strong and stiff, since the filling pieces act to stiffen the teeth greatly against the drag of the magnets. At the same time, the inserted teeth are held in place very securely, because of their enlarged bases, and the filling pieces are held in place securely because of their engagement by the lugs 7 and also because of their frictional engagement with the teeth. The structure is therefore adapted for extremely high peripheral and rotative speeds; and the sides and periphery being perfectly smooth, the resistance offered by the air is only that due to a friction of the air against smooth polished surfaces. It has been found in practice that by this con struction the resistance to rotation of a very high speed rotor has been reduced to ap proximately one quarter of what it was before special provision was taken to reduce air resistance to as low an amount as pos sible.

hat I claim is 1. An inductor rotor comprising a disk having projecting teeth of magnetic material, some of which teeth are integral with said disk and have between them other teeth formed separately from such disk but secured thereto, certain of such teeth having projections bridging the spaces between the teeth and abutting against the adjacent teeth.

2. An inductor rotor comprising a disk having projecting teeth of magnetic material, certain of such teeth having pro ections bridging the spaces between the teeth, and filling pieces between the teeth and held therein by said projections.

3. An inductor rotor comprising a disk having projecting teeth and filling pieces between the teeth, said filling pieces having notches and certain of said teeth having projections fitting within said notches and holding said filling pieces in place, said projections bridging the spaces between the teeth and serving to stilfen the tooth structure.

t. An inductor rotor comprising a disk having radially projecting teeth and filling pieces between the teeth, alternate teeth of said disk integrally formed therewith, the intermediate teeth separably secured to said disk and provided near their outer end with project-ions bridging the spaces between such separately formed teeth and the integral teeth, and serving both to stiffen the tooth structure and to hold in place said filling pieces.

5. An inductor rotor comprising a disk having radially projecting teeth and filling pieces between the teeth and ending flush with the sides of said teeth, alternate teeth of said disk integrally formed therewith, the intermediate teeth separably secured to the disk and provided with means for holding said filling pieces in place.

6. An inductor rotor comprising a disk having projecting teeth, alternate teeth integral with said disk, said disk provided with sockets, between such alternate teeth, for the reception of the bases of intermediate teeth, and intermediate teeth separately formed and fitting within said sockets, such separately formed teeth provided near their outer ends with projections bridging the spaces between such separately formed teeth and the integral teeth, and serving to stiffen the tooth structure.

7. An inductor rotor comprising a disk having projecting teeth, alternate teeth in tegral with said disk, said disk provided with sockets, between such alternate teeth, for the reception of the bases of intermediate z'eeth, and intermediate teeth separately specification in the presence of two subsciib formed and fitting Within said sockets, and ing Witnesses. filling pieces between said teeth, said separately formed teeth having projections mechanically engaging said filling pieces and \Vitnesses: serving to hold same in place. H. M. MARBLE,

In testimony whereof I have signed this FRANK E. RAFFMAN.

ALBERT E. GUY. 

